A research of a Flexible Ethernet (FlexE) technology is started by the Optical Internetworking Forum (OIF) of the International Organization for Standardization (ISO) on March 2015, and the related technical documents are voted and accepted on March 2016. A general structure of the FlexE is shown in FIG. 1. A characteristic of the FlexE is that: multiple Ethernet Physical Layer Links (abbreviated as PHYs) with the same rate are bound to transmit a service with a comparatively high Media Access Control (MAC) rate, for example, four Ethernet PHY channels of 100G are bound to support a user service with the MAC rate of 400G, that is, the user service is transmitted in multiple Ethernet PHYs.
The difference between structures of the FlexE and a traditional Ethernet is that the FlexE has an additional FlexE shim between an MAC layer and a Physical Coding Sublayer (PCS). A function of the FlexE shim is building a calendar with a size of 2×n blocks each having a length of 66 bytes (i.e., 20×n 66b blocks), where n is the number of bound Ethernet PHYs, and each 66b block represents one time slot of 5G.
At a multiplexing side, services with different MAC rates may be encapsulated into corresponding numbers of 66b blocks according to a multiple relationship with the 5G. Every twenty 66b blocks form a sub-calendar, and the calendar with the size of 20×n blocks is distributed in n sub-calendars. For each sub-calendar, every 20×1023 66b blocks are correspondingly added with overhead of one 66b block, for storing a related mapping relationship. Each sub-calendar is transmitted in a single Ethernet PHY of 100G.
Correspondingly, at a de-multiplexing side, n sub-calendars may form a calendar with the size of 20×n blocks, and the user services are extracted from the corresponding numbers of 66b blocks according to the mapping relationship stored in the overhead.